# PolyTech Forum

> PolyTechForum.com website provides free, on-the-go reading and posting access to many engineering Usenet discussion groups, completely anonymously and without requiring registration

This is the extended companion to [llms.txt](https://www.polytechforum.com/llms.txt). It describes how the content on https://www.polytechforum.com is organised and how to read it. Access rules are set by [robots.txt](https://www.polytechforum.com/robots.txt); discovery is served by the sitemap index and feeds listed below.

## How the content is organised

- The site is a set of discussion groups. Each group lives at `https://www.polytechforum.com/{group}/` and lists its threads newest-first, paginated.
- A thread page lives at `https://www.polytechforum.com/{group}/{subject}-{id}-.htm`; its first post is the original question or topic and the remaining posts are replies in order.
- Long threads are split into pages at `{subject}-{id}-{page}.htm`. Each page is a distinct, self-canonical document; it does not canonicalise to page 1.
- Threads that have been consolidated into a main discussion carry a `rel="canonical"` pointing at that discussion. Follow the canonical when it differs from the page URL.
- Pages carrying `<meta name="robots" content="noindex">` are intentionally excluded from indexes and should not be cited as sources.

## Structured data per page type (JSON-LD)

- Home page: `WebSite` with a `SearchAction`.
- Group listing pages: `CollectionPage` with an `ItemList` of the threads on that page, plus `BreadcrumbList`.
- Thread pages: `DiscussionForumPosting` (author, dates, `Comment` entries for the replies on that page) plus `BreadcrumbList`. Threads that read as a question with an answer also emit `QAPage` / `Question` / `Answer`; step-by-step answers may add `HowTo`.
- The FAQ listing emits `FAQPage`.
- The `description` in every thread's JSON-LD and meta tags is a sanitized snippet: quoted text, attribution lines and signatures are removed. Text marked as a quote inside a post body is the earlier poster's words, not the author's.

## Machine-readable surfaces

- [Sitemap index](https://www.polytechforum.com/sitemap.xml) — one sitemap per group; thread `lastmod` reflects the latest post.
- [Atom feed of latest threads](https://www.polytechforum.com/feed.xml) — site-wide; each group also has `https://www.polytechforum.com/{group}/feed.xml`.
- [robots.txt](https://www.polytechforum.com/robots.txt) — the access policy that applies to every client, including AI crawlers.

## Discussion groups

### [&#10705; Industrial Control Group](https://www.polytechforum.com/control/)

Industrial Control engineering and scientific discussions

- Threads: https://www.polytechforum.com/control/ (2,150 threads, 11,708 posts, latest post 2025-04-22)
- Feed: https://www.polytechforum.com/control/feed.xml

### [&#8912;&#8914;&#8912; Computer Numeric Control](https://www.polytechforum.com/cnc/)

All aspects of Computer Numeric Control - machinery as well as software

- Threads: https://www.polytechforum.com/cnc/ (2,667 threads, 23,212 posts, latest post 2022-12-08)
- Feed: https://www.polytechforum.com/cnc/feed.xml

### [&#9178; Electrical Engineering](https://www.polytechforum.com/electrical/)

Electrical Engineering discussions

- Threads: https://www.polytechforum.com/electrical/ (6,731 threads, 62,641 posts, latest post 2026-09-12)
- Feed: https://www.polytechforum.com/electrical/feed.xml

### [&#9178; Electrical Engineering (French)](https://www.polytechforum.com/electrotechnique/)

- Electrical engineering discussions in French.

- Threads: https://www.polytechforum.com/electrotechnique/ (2,176 threads, 18,323 posts, latest post 2026-07-06)
- Feed: https://www.polytechforum.com/electrotechnique/feed.xml

### [&#9178; Electrical Engineering (German)](https://www.polytechforum.com/elektrotechnik/)

- Electrical engineering discussions in German

- Threads: https://www.polytechforum.com/elektrotechnik/ (6,387 threads, 106,357 posts, latest post 2026-09-14)
- Feed: https://www.polytechforum.com/elektrotechnik/feed.xml

### [&#9187; General Metalworking](https://www.polytechforum.com/metalworking/)

All aspects of working with metal.

- Threads: https://www.polytechforum.com/metalworking/ (30,764 threads, 386,357 posts, latest post 2026-09-14)
- Feed: https://www.polytechforum.com/metalworking/feed.xml

### [&#9187; Metalworking Craft](https://www.polytechforum.com/craft-metalworking/)

-metalworking craft discussions

- Threads: https://www.polytechforum.com/craft-metalworking/ (389 threads, 1,300 posts, latest post 2024-02-06)
- Feed: https://www.polytechforum.com/craft-metalworking/feed.xml

### [&#9859; Lego Mindstorms Discussions](https://www.polytechforum.com/mindstorms/)

Lego Mindstorms Disucssions

- Threads: https://www.polytechforum.com/mindstorms/ (168 threads, 346 posts, latest post 2026-06-25)
- Feed: https://www.polytechforum.com/mindstorms/feed.xml

### [&#9859; Using Lego and compatible building blocks](https://www.polytechforum.com/lego/)

Discussion of Lego, Duplo (and compatible) toys.

- Threads: https://www.polytechforum.com/lego/ (1,178 threads, 2,880 posts, latest post 2026-07-31)
- Feed: https://www.polytechforum.com/lego/feed.xml

### [&#9874; Blacksmithing - wrought iron and steel discussions](https://www.polytechforum.com/blacksmithing/)

- Discussions about wrought iron and steel techniques

- Threads: https://www.polytechforum.com/blacksmithing/ (1,041 threads, 7,835 posts, latest post 2026-09-14)
- Feed: https://www.polytechforum.com/blacksmithing/feed.xml

### [&#9879; Material Sciences ](https://www.polytechforum.com/materials/)

- mateirals science discussions

- Threads: https://www.polytechforum.com/materials/ (1,792 threads, 7,465 posts, latest post 2024-09-14)
- Feed: https://www.polytechforum.com/materials/feed.xml

### [&#9881; General Engineering Forum (German)](https://www.polytechforum.com/engineering-de/)

- General engineering discussions in German.

- Threads: https://www.polytechforum.com/engineering-de/ (1,611 threads, 19,919 posts, latest post 2026-08-09)
- Feed: https://www.polytechforum.com/engineering-de/feed.xml

### [&#9881; Mechanical Engineering](https://www.polytechforum.com/mech/)

- Mechanical Engineering discussions

- Threads: https://www.polytechforum.com/mech/ (2,772 threads, 13,173 posts, latest post 2023-12-06)
- Feed: https://www.polytechforum.com/mech/feed.xml

### [&#9881; Model Engineering in the UK](https://www.polytechforum.com/modelengineering/)

Model engineering, metal crafts in UK

- Threads: https://www.polytechforum.com/modelengineering/ (6,652 threads, 53,423 posts, latest post 2026-07-17)
- Feed: https://www.polytechforum.com/modelengineering/feed.xml

### [&#9881; Stationary Engines - UK](https://www.polytechforum.com/uk-engines/)

- Discussions about stationary engines and generators. Topics related mostly to UK.

- Threads: https://www.polytechforum.com/uk-engines/ (5,114 threads, 28,448 posts, latest post 2026-08-08)
- Feed: https://www.polytechforum.com/uk-engines/feed.xml

### [&#9889; Welding Forums](https://www.polytechforum.com/welding/)

Welding of materials for manufacture & repair.

- Threads: https://www.polytechforum.com/welding/ (6,252 threads, 48,963 posts, latest post 2026-09-01)
- Feed: https://www.polytechforum.com/welding/feed.xml

### [✈ RC aircraft models](https://www.polytechforum.com/air/)

- Discussions about RC airplanes and other flying model objects

- Threads: https://www.polytechforum.com/air/ (8,236 threads, 61,195 posts, latest post 2026-07-06)
- Feed: https://www.polytechforum.com/air/feed.xml

### [AutoCAD discussions](https://www.polytechforum.com/autocad/)

- Discussions about AutoCAD® - 3D CAD design, drafting, modeling, architectural drawing, and engineering software. Not affiliated with the software manufacturer.

- Threads: https://www.polytechforum.com/autocad/ (4,367 threads, 15,529 posts, latest post 2024-03-28)
- Feed: https://www.polytechforum.com/autocad/feed.xml

### [Engineering Science (Polish)](https://www.polytechforum.com/engineering-pl/)

- Engineering science discussions in Polish.

- Threads: https://www.polytechforum.com/engineering-pl/ (4,596 threads, 39,458 posts, latest post 2026-08-20)
- Feed: https://www.polytechforum.com/engineering-pl/feed.xml

### [General Robotics Forum](https://www.polytechforum.com/robotics/)

All aspects of robots and their applications.

- Threads: https://www.polytechforum.com/robotics/ (4,978 threads, 28,074 posts, latest post 2026-09-07)
- Feed: https://www.polytechforum.com/robotics/feed.xml

### [Metallurgy discussions](https://www.polytechforum.com/metallurgy/)

- discussions about the properties of metals and alloys.

- Threads: https://www.polytechforum.com/metallurgy/ (898 threads, 3,268 posts, latest post 2025-10-21)
- Feed: https://www.polytechforum.com/metallurgy/feed.xml

### [Model Railroad Forum](https://www.polytechforum.com/trains/)

- Discussions about scale railroad models. All standard scales are represented here.

- Threads: https://www.polytechforum.com/trains/ (8,004 threads, 64,621 posts, latest post 2025-11-09)
- Feed: https://www.polytechforum.com/trains/feed.xml

### [Model railroading in the UK](https://www.polytechforum.com/uk-trains/)

- Discussions about railroad modeling, mostly related to UK topics. All standard scales are covered here.

- Threads: https://www.polytechforum.com/uk-trains/ (6,299 threads, 63,008 posts, latest post 2025-05-14)
- Feed: https://www.polytechforum.com/uk-trains/feed.xml

### [Model rockets forum](https://www.polytechforum.com/rockets/)

- Discussions about model rocketry

- Threads: https://www.polytechforum.com/rockets/ (6,331 threads, 81,290 posts, latest post 2026-01-04)
- Feed: https://www.polytechforum.com/rockets/feed.xml

### [PRO/Engineer (Creo) discussions](https://www.polytechforum.com/pro-engineer/)

- discussions about PRO/Engineer® (now Creo Elements®) CAD system. Not affiliated with the software manufacturer.

- Threads: https://www.polytechforum.com/pro-engineer/ (2,894 threads, 11,195 posts, latest post 2023-12-06)
- Feed: https://www.polytechforum.com/pro-engineer/feed.xml

### [RC and scale modeling (French)](https://www.polytechforum.com/moidels-fr/)

- RC and scale models, including railroad models (in French)

- Threads: https://www.polytechforum.com/moidels-fr/ (3,829 threads, 18,120 posts, latest post 2026-08-07)
- Feed: https://www.polytechforum.com/moidels-fr/feed.xml

### [RC and scale modeling (German)](https://www.polytechforum.com/models-de/)

- RC and scale model discussions in German.

- Threads: https://www.polytechforum.com/models-de/ (4,670 threads, 50,306 posts, latest post 2026-05-25)
- Feed: https://www.polytechforum.com/models-de/feed.xml

### [RC and scale modeling (Italian)](https://www.polytechforum.com/models-it/)

- RC and scale models discussions (in Italian)

- Threads: https://www.polytechforum.com/models-it/ (11,511 threads, 54,322 posts, latest post 2026-09-07)
- Feed: https://www.polytechforum.com/models-it/feed.xml

### [RC and scale modeling (Polish)](https://www.polytechforum.com/models-pl/)

- RC and scale modeling discussions (in Polish)

- Threads: https://www.polytechforum.com/models-pl/ (11,747 threads, 48,905 posts, latest post 2026-02-02)
- Feed: https://www.polytechforum.com/models-pl/feed.xml

### [Scale modeling discussions](https://www.polytechforum.com/scale/)

- Discussions about techniques, materials, supplies and other aspects of scale modeling. All types and scales of models are covered here.

- Threads: https://www.polytechforum.com/scale/ (19,727 threads, 109,807 posts, latest post 2025-11-16)
- Feed: https://www.polytechforum.com/scale/feed.xml

### [Solidworks CAD Design software](https://www.polytechforum.com/solidworks/)

- Discussions about Solidworks® CAM software by Dassault Systèmes. Not affiliated with the software manufacturer.

- Threads: https://www.polytechforum.com/solidworks/ (13,023 threads, 68,460 posts, latest post 2026-02-21)
- Feed: https://www.polytechforum.com/solidworks/feed.xml

### [⚗ Polymers Forum](https://www.polytechforum.com/polymers/)

- discussions about the science and properties of polymers (plastics)

- Threads: https://www.polytechforum.com/polymers/ (1,069 threads, 3,436 posts, latest post 2026-06-11)
- Feed: https://www.polytechforum.com/polymers/feed.xml

### [🔒 Lockmithing and Lockpicking Discussions](https://www.polytechforum.com/locksmithing/)

Discussions about all matter related to locks and safes

- Threads: https://www.polytechforum.com/locksmithing/ (2,434 threads, 20,469 posts, latest post 2023-03-16)
- Feed: https://www.polytechforum.com/locksmithing/feed.xml